Renault boss Eric Boullier says Bruno Senna has boosted team

Although Senna's race hopes were effectively dashed by an error at the first corner, the way the Brazilian dealt with the pressure of the weekend and put himself seventh on the grid has left Boullier convinced he did the right thing in shaking up his driver line-up.

"I was more than happy to see all my people in the garage applauding at the end of Q2 and Q3 with a smile on their face," said Boullier. "It was the first time that had happened since Malaysia.

"It is important to have your people, who work all day and all night, be happy. This is for me very important; this is the way I can get the best out of our guys."

Senna's mistake at the first corner, where he braked slightly too late and slid into Jaime Alguersuari, has highlighted how he still needs more track time to fully get used to race driving again - but there were other aspects of his approach that delighted Boullier.

"His obvious weakness was the limited track time since January, so he needs more time to get his confidence back in exploiting the car," he said.

"His strength was his quietness and building up his speed, and working very well with the engineers. You could sense he felt at ease with the engineers and the environment, and he just took it step by step.

"It was also hard for him. With the late confirmation it was not the ideal scenario, and obviously the weather conditions at the first of the weekend were tough - especially on a very challenging track.

"The next races will be challenging for him, especially in Monza with no downforce, which makes the car difficult to drive. But definitely his confidence is back to the maximum - so I am sure he can do it."

Boullier said the pressure was not just on Senna, either, because the boss himself had to shoulder the responsibility for the Brazilian delivering in the wake of the controversial dropping of Nick Heidfeld.

"You have to question a lot of people before you take a decision like that," he said. "You obviously make some people unhappy and it is always challenging for my job - because if I fail....

"Once you push the button and choose to go for a different scenario you have to take the responsibility."

And on the back of an incredibly hard year, which has included a fall from form and the loss of Robert Kubica, Boullier says he was never under any illusion that things would get easier after an encouraging first season in charge in 2010.

"It is tougher and tougher as obviously people expect more," he said. "The first year is easy, you step in - here is the car and driver, go ahead. So you go ahead - the machine is already working.

"In the second year we have started to restructure and influence change, and people are waiting for you to deliver. We are obviously not delivering exactly as we expect, so it is a little bit tougher. But people need to understand that you cannot change enough and make sure you can win in F1 within a year or two.

"I am not chasing excuses. It takes time to rebuild confidence, have a group of people working together and getting the sponsors and the drivers in place to have this positive loop, to make your team win again. It is more challenging."